Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

(opensolaris section 3lib)
man page for libc_db

libc_db(3LIB)							Interface Libraries						     libc_db(3LIB)

NAME
libc_db - threads debugging library SYNOPSIS
cc [ flag ... ] file ... -lc_db [ library ... ] #include <proc_service.h> #include <thread_db.h> DESCRIPTION
The libc_db library provides support for monitoring and manipulating threads-related aspects of a multithreaded program. There are at least two processes involved, the controlling process and one or more target processes. The controlling process is the libc_db client, which links with libc_db and uses libc_db to inspect or modify threads-related aspects of one or more target processes. The target processes must be multithreaded processes that use libc. The controlling process mignt or might not be multithreaded itself. The most commonly anticipated use for libc_db is that the controlling process will be a debugger for a multithreaded program, hence the "db" in libc_db. The libc_db library is dependent on the internal implementation details of libc. It is a "friend" of libc in the C++ sense, which is pre- cisely the "value added" by libc_db. It encapsulates the knowledge of libc internals that a debugger needs to manipulate the threads- related state of a target process. To be able to inspect and manipulate target processes, libc_db makes use of certain process control primitives that must be provided by the process using libc_db. The imported interfaces are defined in proc_service(3PROC). In other words, the controlling process is linked with libc_db and calls routines in libc_db. In turn, libc_db calls certain routines that it expects the controlling process to provide. These process control primitives allow libc_db to: o Look up symbols in a target process. o Stop and continue individual lightweight processes ( LWPs) within a target process. o Stop and continue an entire target process. o Read and write memory and registers in a target process. Initially, a controlling process obtains a handle for a target process. Through that handle it can then obtain handles for the component objects of the target process, its threads, its synchronization objects, and its thread-specific-data keys. When libc_db needs to return sets of handles to the controlling process, for example, when returning handles for all the threads in a tar- get process, it uses an iterator function. An iterator function calls back a client-specified function once for each handle to be returned, passing one handle back on each call to the callback function. The calling function also passes another parameter to the iterator func- tion, which the iterator function passes on to the callback function. This makes it easy to build a linked list of thread handles for a particular target process. The additional parameter is the head of the linked list, and the callback function simply inserts the current handle into the linked list. Callback functions are expected to return an integer. Iteration terminates early if a callback function returns a non-zero value. Other- wise, iteration terminates when there are no more handles to pass back. INTERFACES
The shared object libc_db.so.1 provides the public interfaces defined below. See Intro(3) for additional information on shared object interfaces. td_init td_log td_sync_get_info td_sync_get_stats td_sync_setstate td_sync_waiters td_ta_clear_event td_ta_delete td_ta_enable_stats td_ta_event_addr td_ta_event_getmsg td_ta_get_nthreads td_ta_get_ph td_ta_get_stats td_ta_map_addr2sync td_ta_map_id2thr td_ta_map_lwp2thr td_ta_new td_ta_reset_stats td_ta_set_event td_ta_setconcurrency td_ta_sync_iter td_ta_sync_tracking_enable td_ta_thr_iter td_ta_tsd_iter td_thr_clear_event td_thr_dbresume td_thr_dbsuspend td_thr_event_enable td_thr_event_getmsg td_thr_get_info td_thr_getfpregs td_thr_getgregs td_thr_getxregs td_thr_getxregsize td_thr_lockowner td_thr_set_event td_thr_setfpregs td_thr_setgregs td_thr_setprio td_thr_setsigpending td_thr_setxregs td_thr_sigsetmask td_thr_sleepinfo td_thr_tsd td_thr_validate FILES
/lib/libc_db.so.1 shared object /lib/64/libc_db.so.1 64-bit shared object ATTRIBUTES
See attributes(5) for description of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsl (32-bit) | | |SUNWcslx (64-bit) | +-----------------------------+-----------------------------+ |MT-Level |Safe | +-----------------------------+-----------------------------+ SEE ALSO
Intro(3), td_ta_new(3C_DB), attributes(5), threads(5) SunOS 5.11 24 Mar 2004 libc_db(3LIB)

Featured Tech Videos